Tubular electromagnet potential indicator



Sept. 5, 1950 c. c. SITTLER TUBULAR ELECTROMAGNET POTENTIAL INDICATOR Filed July 28, 1944 Patented Sept. 5, 1950 1 'can-creamer,eiemrruyngm; I phtanonmoves, 1944,,Serial;N0..547,060 '4'Claims. (ohm-95') '1 -'Ihi s1inventi on relates to a potential indicator or voltage testentoindicate the voltage. of electric lines.

There are numerous ivoltage testers with v.in-

dicators in commercialuse but-most of them are cumbersome to handle clo :not have the necessary requirements as to-:safety,. and are incapable of beingmeadeasilyand quickly.

The primary object of the .present invention to provide a new .and improved potential .indicator which can be applied. or positioned easily andreadily to the terminals of the ,line being t sted, andthe voltageindicated will be in plain sightof .the person using the indicator or conducting .thetest. a 1

Another important object .is to provide a po- ,tential indicator orvoltage tester of an, improved .form and of .new and .novel character whereby the operator or, line tester .may hold the body in one hand, and the extension in the other hand for-making contact easily with thetwo contacts orlinesto he tested, and while sojholding the .devicemaysee at a. glance the voltage registered on he indi ator.

Eurtherfimportant objectsof theinventionreide in the provision of 'a :device which freely .and quickly .t ests .aIpotential and determines substantially the voltage of both alterriatingand direct. current, which is. simple, compact and durablein construction, which has its. indicator or indicating mechanism arranged in v, plain sight 01f the operator by locating the same .at the top end. .ofiithe casin o h u in which composed of rel i ly w. and s ple parts and, therefore;'isnotlikely to get. outof order, .which has a rigid ,nrod or probe ranged riie dlylat the lower end or the casing or'hou ing witha s c.- ond .iprod or probe at an end of ct-flexible .conductor protruding. f I:Qm,the casing or housing i. for quick and ready application to the terminals of a line .to be tested, which is rigid .andeas ilyrnanipulated, and which may.be.manu-factured.read .ilyatlow cost.

Numerous .other objects andladvantages will be,apparent.throughoutthe.progress.,of..the spe- 5 .cificationwhich follows/ t a I unselected embodiment of the inventionisil- .lustrated .in the accompanying drawings where- .in'

Fig. 1 is a detail elevational viewofapotential I2 Fig.5isardetailtonplan view; I

is .a.;detai1 perspective view of theindicator;

,Fig. 6 is. ajdetail sectional, view showing a'double coil oiusolenoid construction;

Fig.17;i.s .a..detail sectional .view showing one manner .in which-therigidlower prod or probe maybe electrically connected to the coil or solenoidrand Fig. 8 jis a view similar to Fig.7 but showing a modified form of probe or prod connection to the coil? the ,Drod bein threaded into the. core of thegoil. I I

'IIhe particular jdevice Therein shown for the purpose of ,.illustrating the invention comprises an inner support or.iframe I of relatively cylindrical construction, being cut away at its upper end'to provi'de spaced ,legs 12 to receive an indicator-1'. 1

*Theindicatorfi is of relatively'circular or disklike "formation'havinga thickened part .4 and a thinner parti5,the thickened part 4 being some what.more than half .theflarea, as clearly shown 'in'F'i g.f5. The thinner portion'Sfits inzbetween the spaced legs 5 of an operating member! which is pivotallymounted 'at'B to the circular, .disklike indicatorj3. -'Theindicatorgi-l is revolubly mounted on .a shaftor axis "9 which extends through an .openin qw :in;the indicator and engages and'is supported-at I' l bythe legs .2 of the sunporting structure], as clearly shown in Fig. 3. The operating rnember "'l is ,piV 0ta1ly connected at "I2 to a yok e "l.3 li ed to the upperend of a sof tiiron solenoid corefi't. The solenoid core M operates 'in'the central opening I5 of a solenoid .0011 IS. The solenoid Coil 1.6 is wound upon'a spool H of fiber or other conventional material and has .upper an'dlower iheads It and), respectively. Thecoil lfilmaybe retained in proper .positionfby means. of screwsfifl passingthrough the lower cylindrica1 parto'f the supporting memlier ;l and engaging the lower head .i 6 of the coil, as clearlyshowninfiig. 2.

. The .coil 1.6.15 made upof enamelled magnet wire and has opposite 1eads2l and .2-2, theleads .Zl .and;..=2 2 .being .the oppositeends of the ,wire .of .which 1the coi1 ismade. one' lead ,Zlfis electrically connected to rafrigid iprodpr probe .23 extending ,through the hottom cap .24, while the othenlead 22 extendsthrough an openingformed :in the support 1 and ithrougl the device casing 25,, 215 .6. said jlead :22 .being electrically connected to a rflexibleiconductor ord 26 .having a prom-0r -.pr ob,e .2] electrically connected :at its lower end,

as clearly shownin 1;.

A coil spring 28 is interposed between the head l8 of the coil I 6 and the yoke l3 on the iron core l4 so as to urge the core in a predetermined position and return it to original position after it has been operated by electric energy. When the prods 23 and 21 are placed in electrical contacting engagement with the electrical contacts of the line being tested, the core l4 will be drawn down-1 Wardly in the usual manner and pull the member 1 downwardly against the tension of the spring 28, causing rotative movement of the circular in-- dicator 3 about its pivot 9. A top 29 is operatively secured to the upper end of the casing 25, and this top has an elongated sight slot or area 30 through which the indicia member 3| on the indicator 3 may be seen. The indicia 3| is circumferentially arranged about the thickened portion 4 of the The invention provides a simple, inexpensive, compact indicating device which can be easily handled and manipulated by the operator, and which canbe read quickly and readily. In actual practice the operator holds the casing in one hand so that the prod 23 is in contact with one contact, and the prod 21 held in the other hand is put into engagement with another contact. The upper end of the device will then be facing the operator, whereupon the operator can read the indicia or scale quickly and readily. The invention further provides the use of a spring having an urging action against the downward moveindicator member 3, as clearly shown in Fig. 5, the l indicia being divided so as to indicate voltage for both direct and alternating current, the, indicia being so arranged that the alternating current and the direct current may be shown directly through the opening 30 in the top 29.

The spring 32 is locatedin the opening in the coil at the bottom of the coil against which the bottom 33 of the iron core engages, whereby the range of the indicia or the scale may be accurately determined, the energization of the coil causing the core to move downwardly against the spring 32 whereupon the downward movement of the core will be limited by the spring 32, the spring creating an urging action upwardly against the downward movement of the core. The device, as shown, may have the scale or indicia 3| set for voltages from 110 volts or less to 660 volts more or less, determined by conditions. However, the present device is indicated as operating on a maximum line voltage of 660 volts. To reduce the danger to the operator and to the device should the coil develop a short circuit in its windings, as by insulation failure due .to overloading or other reasons, it may be desirable to make the coil. in two or more sections 34 and. 35, as shown in Fig.6. The sections may be mounted in alinement and electrically connected in series. InLsuch arrangement the voltage across each section is much lower than the line voltage.- Where .twocoils of identical size are used, each absorbs one-half of the line voltage, so that, ifa short circuit develops in either section, the voltage across the injured section will be only half 'whatlitwould be in a device built with a single coil. As a consequence, the effects of a short circuit in the device are considerably minimized in the, multi-coil arrangement.

The outer casing 25 may support the upper and lower ends 29 and 24, respectively, in any convenient manner, such as by screws 36 passing through the outer casing 25, as shown in Fig. 6.

The lower rigid prod 23 may be screw threaded into the bottom cap 24, as shown in Fig. 7, the end of the prod 31 being screwthreaded and engaging a nut 38 suitably embedded in the bottom cap 24, the lead 2| from the coil being electrically connected to the nut 38.

In Fig. 8 the lower prod 23 may have its upper end threaded, as indicated at 33, to engage threads 40' about the opening in 'the coil, the lead 2| being electrically connected' 'toanextension 4| formed in the bottom member I9 of the coil.

The outer casing 25 and the outer caps and 29 are made of insulating materialsuoh-asf-fiber, although any other insulatin material may be used; also, the supporting member is preferably made of suitable insulating'matrialf ment of the core, as well as providing a safety feature in the device by the use of two separate coils hooked up in series.

The indicia 3| may be of luminous paint so that the same may be seen in the dark.

' Changes may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention or sacrificing any of its advantages, and the right is hereby reserved to make all such changes as fairly fall within the scope ofthe following claims. t

The invention is hereby claimed as follows:

1. A potential indicator comprising a body, a disk member arranged in the upper part of the body, said disk member having a thick and a thin part, indicia peripherally arranged on the thick part of the disk to indicate certain voltages, means for rotatably mounting the. disk on ahorizontal axis, a solenoid including a pair of coils wound in series in the body,.a core for said solenoid, an operating member having spaced arms operatively connected to the disk and between which arms the thin part of the disk is arranged, and a yoke on the core and operatively connected to the operating member whereby movement of the core will impart rotative movement to the disk memher.

'2. A potential indicator comprising a hollow tubular body, a disk member arranged inside the body at the upper end thereof and having. a thick and a thin part, indicia on the thick part of the disk member to indicate certain voltages, means for rotatably mounting the disk member ona horizontal axis, a solenoidincluding a ,pair of coils wound in series in the body, a core for said solenoid, an operating member having spaced arms operatively connected to the disk member and between which arms the thin part of the disk isharranged, a yoke on the core and operatively connected to the operating member whereby movement of the core will impart rotative movement to the disk, a flexible conductor extending through the body near the lower end thereof and electrically connected to the solenoid, a prod at the end of the conductor, a rigid prod fastened to the body at the bottom thereof and electrically connected to said solenoid, and a topcap on the body in juxtaposition with respect to the thick part of the disk member, said cap having an opening therein through which certain of the indicia on the thick part of the disk member is visible.

3. A potential indicator comprising an elongated tubular body having a, prod supporting bottom closure and a top closure having a sight area, an indicator pivoted in said body on an axis extending along a diameter thereof and. having tion, an elongated tube closed at the bottom, a

top closure having a sight area centrally disposed therein, a supporting structure received in said tube, a solenoid coil carried by said structure at its lower end, a core slidable in said solenoid and having a portion extending above its upper end, a head on said core, a helical spring surrounding said portion and engaging said head and upper end, an indicator movable beneath said top closure for inspection through said sight area, a pivot for said indicator extending diametrically of said tube and carried by said support and a link connecting said head to said indicator so as to move the said indicator arcuately about its pivot.

CARL C. SITI'LER.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 79,103 Calvert June 23, 1868 623,861 Young Apr. 25, 1899 1,148,218 Clark July 27, 1915 1,712,560 Huggins May 14, 1929 1,978,916 Stolp et a1. Oct. 30, 1934 2,290,760 Mehaffie July 21, 1942 2,363,799 Mahurin Nov. 28, 1944 2,366,991 Wich Jan. 9, 1945 2,426,050 Radwanski Aug. 19, 1947 OTHER REFERENCES Electrical Review, page 231, February 5, 1926. 

